Problem is though that your questions, apart from No 1 (and I'm not sure that is answerable), are probably too broad to be answered successfully. An even bigger problem is that Murano trained workers have moved all over the world to work and train other people. And people are very good at imitating styles that sell.

Chalet is sometimes signed though...

Really all you can do is look and learn and ask about individual pieces of glass. Colours, shapes and sometimes finishes are often clues

Hi i believe the French have been using Avventurine for at least as long as the Italians , but i may be wrong . Green Avventurine comes to mind . I believe yours may have gold leaf rather than avventurine if you are talking about the ruby ones above .jp

Hi,looking on some of my books, it looks that the first family using a brown "avventurina" based on copper powder, was Miotto, around the XVII century. Instead the French technique (with chrome, more green color, 1860 approx.)) looks to be very similar to a chineese glass of XVIII century.

Hi and welcome! Beautiful glass bowl and vase. I love the red glass. It looks like your vase is vertically ribbed and the bowl is spiral. Several companies made the ruby glass. The most famous are Barovier & Toso, Salviati, and AVeM, but there may be more recent pieces. The Venetian glass is copied by glassmakers who admire the work.

Murano glass tends to have a certain look, but it can be hard to draw sharp lines between countries in the appearance of the glass. There was exchange in people making the glass and exchange of the glass itself. For example, Salviati sold blanks to Moser of Austria (later Czech) around the turn of the century. Moser decorated them. Some of the decorated pieces are in the catalogs of both companies -- completely okay, because they both played a part in the making. I noticed that some Moser designs are sold in Venice glass stores at the present time. I don't know if they are local copies or if Moser made them for sale.

About Chalet glass -- the thing I look for in this glass is transparency and a signature. Unless I see these two things, I am never certain. Many companies make glass similar to Murano. I am not sure that Chalet is always signed, but I shy away if I don't know things for sure. I have a couple of shelves of mistake buys.

There are some Murano pieces with frilly edges. Plain or rolled rims tend to be most popular, however. Hope this helps some.

I'd love to hear answers to these questions. I suspect they'd be long, with lots of qualifiers. They're great questions, but ones that will occupy you for much of your collecting life.

I'll add what I can to the easiest question. According to someone who worked there, the great majority of Chalet was signed. I've found that much of the glass that isn't signed is Czech, rather than Murano. Also, I suspect that over the course of Chalet's quite complex corporate life, they made some quite different glass from what we (at least, me) expect of Chalet. One of the originals from Chalet was making glass under the name of "Rossi Artistic Glass" until recently.

The first copper based aventurine was made in the 15th century in Murano- by accident. It was an expensive and difficult material in that it required cooling in the pot - after which the pot was useless. The material came out as one big lump which had to be hammered into usable shards by hand. Should you ever get to the Mevlevi museum in Istanbul http://english.istanbul.com/Content.aspx?CatId=3584&Type=detail you may see an ink well in solid panel cut aventurine which in Turkish is called "star stone" - and certainly the earliest I've ever seen.Green Chromium based aventurine was first made in France in 1865.